Prospect Spotlight: Marcelo Mayer, SS, Boston Red Sox

Background
A left-handed hitter out of Eastlake HS, Mayer stands 6’3” and 188 lbs. After impressing in showcase events and hitting .392/.555/.886 in his senior year, Mayer was the #1 ranked prospect by MLB Pipeline. On draft day, the Red Sox selected Mayer with the 4th overall pick and signed him to an at-slot deal of $6.66M.
Hit Tool
Marcelo’s best tool is his hit tool. His stance begins open from the left side and upright, with hands pulled in and at shoulder level. A slight rock back and toe-tap to a closed stance, Mayer very simply uncoils and whips the bat through the zone with very little other body movement. His bat speed is plus and is generated by very quick hands, and with little wasted movement comes through the zone quickly and without delay once he decides to pull the trigger. His bat path is flat but well-controlled and not ‘slappy’. He does put balls in the air especially down in the zone. His bat stays in the zone a long time through the swing and maximizes contact for line drives. Mayer uses the entire field but stays pull side and up the middle on balls up in the zone. He’s able to put the good part of the bat on the ball in any part of the zone and even looks comfortable with a wooden bat, which is not always a given with high school prospects.
Approach
While not a patient hitter, Mayer has a good understanding of the strike zone. As can be the case with prep stars with plus hit tools, he has a swing-first approach, but not at the expense of striking out. His zone coverage is very good, and the bat path helps him make lots of contacts while keeping his swing and miss rate down. He’s able to pick up spin well and frequently spits on pitches breaking out of the zone. This type of approach will keep strikeout totals low but could see modest walk rates unless pitchers are avoiding him.
Power
The power is where the projection really starts for Marcelo, with impressive raw power, but really needs to develop his in-game power which is currently only average. He’s currently a bit skinny through the hips, but only 18 and has plenty of frames to fill into and time to do it. The swing is line drive orientated, but his bat speed and contact skills hint at more power as he matures. Perfect Game recorded a max exit velocity for Mayer of 90 mph, which is 93rd percentile for the year and a good reading for a prep prospect. With a swing relying so heavily on his use of hands, a swing change could be needed to use more of his upper body strength, but it’s unclear if the Red Sox or Mayer would be willing to tinker with such a strong hit tool. Look for average power, or about 15 home runs a year, with a chance for more.
Speed
Marcelo is athletic and an average or slightly above-average runner who’s shown to be a good base stealer. In high school, he managed to swipe 18 bags in 34 games, then added 7 more on 8 attempts in rookie ball. The speed is probably his worst tool but in no way a negative. He’s looking like a willing and capable base stealer and should project to steal 12-18 bags a year if he maintains his current footspeed.
Defense
A good defender, with effortless natural movements and very good hands. Mayer makes fielding grounders look easy and has an above-average to plus arm. While he has the ability to play anywhere in the infield, he’ll likely stay at shortstop unless blocked by a gold glove caliber defender or franchise cornerstone.
Summary
Mayer’s hit tool and power potential make him a very intriguing prospect. High school players rarely have as high a floor as Meyer either. What will likely determine how successful he becomes in the big leagues, and in dynasty leagues, is how much power he’s able to tap into. Players with a strong hit tool tend to get to their top-end power projects so there’s reason to believe Mayer will get there. Look for him to go within the top two or three picks of your dynasty supplemental drafts and probably the favorite to go first overall.
Scouting Grades
Hit Raw Power Game Power Speed Field FV
60 60 50 50 55 50